Krammer 2002 Category: Asymmetrical biraphid
BASIONYM: Cymbella neoleptoceros Krammer 2002
Contributor: Loren Bahls - June 2016
Length Range: 12-46 µm
Width Range: 5.4-12.5 µm
Striae in 10 µm: 9-11 at the valve center, up to 13 at the apices
Valves are dorsiventral and rhombic-lanceolate with rounded apices. The dorsal margin is moderately arched. The ventral margin is somewhat less arched and slightly tumid in the largest specimens. The axial area is a bit wider than the raphe and lies just ventral of the valve mid line. The central area is a somewhat wider continuation of the axial area and, in some specimens, is defined by one or two shorter striae on the dorsal side. The raphe is distinctly lateral and bowed, narrowing toward the proximal and terminal ends. Proximal raphe ends are deflected ventrally and terminate in slightly inflated pores. Distal raphe fissures are deflected dorsally at about a 45 degree angle. Striae are nearly parallel at the valve center, becoming strongly radiate at the apices. The areolae are very distinct in LM and number 18-22 in 10 µm. A stigma is lacking.
Basionym: Cymbella neoleptoceros
Author: Krammer 2002
Length Range: 21-51 µm
Width Range: 8-12 µm
Striae in 10 µm: 8.5-11 at the valve center, 12 near the apices
Krammer, K. (2002). The genus Cymbella. Diatoms of Europe. Diatoms of the European Inland Waters and Comparable Habitats 3: 1-584.
Most specimens of C. neoleptoceros that are shown on this web page were collected from Lower Wolverine Lake in northwest Montana (photo below). At the time of collection, pH of this lake measured 9.01 and electrical conductance measured 100 µS/cm. The remaining specimen was collected from a kettle lake in North Dakota. This lake had a pH of 9.00 and specific conductance of 1693 µS/cm. Krammer (2002) reports this widespread species as epiphytic and epilithic in brooks and lakes of the Alps and abundant in many calcium-saturated rivers and lakes of the Karst region of the Balkans. It has been reported from oligotrophic to slightly mesotrophic waters with average electrolyte content.
Lower Wolverine Lake, Lincoln County, Montana: home of Cymbella neoleptoceros
Credit/Source: Loren Bahls